Self cleaning conveyor with roller scraper and debris reduction skirt

ABSTRACT

Disclosed herein is a method and apparatus for a street sweeper having a conveyor assembly. The conveyor assembly has a pair of rollers and a conveyor belt connected therebetween. The conveyor assembly is provided with debris skirts to lift the edge of the conveyor belt to prevent debris from traveling over the edge of the conveyor belt. The conveyor belt is formed into a concave orientation. The debris skirts is also connected to a rub rail to provide a dynamic seal along the length of the conveyor belt edges. The conveyor assembly is also provided with a roller scraper for removing debris accumulated upon the rollers. The roller scraper is adapted to envelop a portion of the roller. The conveyor assembly is also provided with a liquid delivery system for assisting in the removal of debris from the roller.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a conveyor belt debris removal systemmost commonly on street and floor sweepers though other applicationswhere particles are transported would be applicable. The conveyor beltdebris removal system may be provided with an apparatus configured toform the belt into a particular shape along at least a portion of therun of the conveyor belt. The conveyor belt debris removal system mayalso be provided with a cleaning mechanism for removing debris from aconveyor belt roller disposed at ends of the conveyor belt apparatus.

2. Background

Street sweepers are a common necessity to maintaining the safety andbeauty of streets and highways throughout the world. Street sweeperscome in a variety of shapes and sizes for a variety of differentfunctions. Some surfaces must be maintained meticulously clean forsafety purposes, such as airport runways, taxi-ways, and helicopterlanding strips. Other surfaces require cleaning to prevent flooding,such as sweeping the leaves from highways and streets to preventditches, culverts and storm drains from becoming clogged and preventingthe runoff of snow melt and storm water.

In small towns and suburban neighborhoods, small, quiet, dust-less, andpollution free street sweepers are demanded. In order to provide a moreefficient and durable street sweeper, a conveyor belt debris removalapparatus may be applied to convey the debris from the surface beingcleaned to a debris collection bin in the street sweeper assembly.Conveyor belt debris removal systems suffer a drawback because of theflexible nature of the rubber or plastic conveyor belts.

During debris collection and removal, the conveyor belt may vibrate. Thevibrations may cause debris to travel to the edges of the conveyor beltand fall into the interior space between the upper and lower revolvingconveyor belts. The debris may then travel to the ends of the conveyorbelt assembly and become attached to the rollers disposed at the ends ofthe conveyor assembly. The debris interferes with the rollers'frictional interaction with the conveyor belt causing the conveyor beltto stretch and slip over the rollers. The debris attached to the rollerscauses increases wear on the debris removal system and may cause acatastrophic malfunction of the system.

In a conveyor belt debris removal system, tension must be maintained inthe belt at all times, otherwise the belt will slip and be preventedfrom rolling as the drive roller turns causing the operation of theconveyor to be impeded or ultimately fail.

It can be seen that there is a need for a conveyor belt debris removalsystem provided with an apparatus configured to form the belt into aparticular shape along at least a portion of the run of the conveyorbelt to prevent debris from falling off the conveyor belt and damagingthe debris removal system. It can also be seen that there is a need fora cleaning mechanism for removing debris from a conveyor belt rollerdisposed at ends of the conveyor belt apparatus to ensure that tensionis maintained in the conveyor belt so that the frictional engagementbetween the rollers and the conveyor belt remains optimized.

By implementing this invention, the conveyor is able to operate forlonger periods of time with less maintenance. The present inventionfulfills these and other needs, and addresses other deficiencies ofprior art implementations.

SUMMARY OF THE INVENTION

To overcome the limitations in the prior art described above, and toovercome other limitations that will become apparent upon reading andunderstanding the present specification, the present invention disclosesa conveyor belt debris removal system. The conveyor belt debris removalsystem may be provided with an apparatus configured to form the beltinto a particular shape along at least a portion of the run of theconveyor belt.

The conveyor belt debris removal system may also be provided with acleaning mechanism for removing debris from a conveyor belt rollerdisposed at ends of the conveyor belt apparatus.

An apparatus in accordance with the principles of the present inventionmay include a street sweeper including a conveyor assembly. The conveyorassembly includes a first driving roller and a second roller mounted onan axle. The second roller has an associated bearing assembly at eachend of the axle. The apparatus also includes a conveyor belt havingopposing edges. The belt is operatively connected to the first drivingroller and the second roller. The apparatus also includes at least onedebris skirt associated with an edge of the conveyor belt. The debrisskirt is positioned to lift the edge of the conveyor belt, therebycausing the conveyor belt to follow a concave orientation.

Other embodiments of a system in accordance with the principles of theinvention may include alternative or optional additional aspects. Onesuch additional aspect of the present invention is that the at least onedebris skirt includes a pair of debris skirts. Each debris skirt isassociated with opposing edges of the conveyor belt adjacent to thesecond roller.

Another aspect of the present invention is that each debris skirtincludes an extension flange substantially covering at least part of theends of the axle and the associated bearing assemblies.

Another aspect of the present invention is that the street sweeper alsoincludes a rub rail associated with each debris skirt. The debris skirtand associated rub rail cooperatively form a dynamic seal with theconveyor belt along the edges of the conveyor belt and cooperativelylift the conveyor belt edges along a length of the conveyor belt formingthe conveyor belt concave shape.

Another aspect of the present invention is that the rub rail and thedebris skirt are associated via a mitered joint.

Another aspect of the present invention is that the street sweeper alsoincludes a roller scraper associated with the second roller. The rollerscraper envelops at least a portion of the second roller.

Another aspect of the present invention is that the roller scraperincludes a scraping surface spaced a predetermined distance from asurface of the second roller along an entire extent of the secondroller.

Another aspect of the present invention is that at least the secondroller is crowned at a center point of the roller and the roller scraperincludes a centrally located ridge associated with the crowned centerpoint of the second roller.

Another aspect of the present invention is that the roller scraper alsoincludes a pair of sloping sides extending from the ridge to outer edgesof the roller scraper and following a rollout of the second roller todirect debris away from the second roller and the conveyor belt.

Another aspect of the present invention is that the street sweeper alsoincludes a liquid delivery assembly associated with the second rollerand the roller scraper. The liquid delivery assembly includes at leastone hose, at least one spout, and at least one nozzle associated witheach at least one spout.

Another apparatus in accordance with the principles of the presentinvention may include a conveyor assembly including a roller mounted onan axle and having an associated bearing assembly at each end of theaxle. The conveyor assembly also includes conveyor belt operativelyconnected to the roller and a pair of debris skirts associated with eachedge of the conveyor belt. The debris skirts lift the edge of theconveyor belt forming the conveyor belt into a concave orientation.

Another aspect of the present invention is that the debris skirts alsoinclude an extension flange substantially covering the ends of the axleand the associated bearing assemblies.

Another aspect of the present invention is that the conveyor assemblyalso includes a rub rail associated with each debris skirt. The debrisskirts and associated rub rails cooperatively form a dynamic seal withthe conveyor belt along the edges of the conveyor belt and cooperativelylift the conveyor belt edges along a length of the conveyor belt formingthe conveyor belt concave orientation.

Another aspect of the present invention is that the rub rail and thedebris skirt are associated via a mitered connection.

Another aspect of the present invention is that the conveyor assemblyalso includes a roller scraper associated with the roller. The rollerscraper envelops at least a portion of the roller.

Another aspect of the present invention is that the roller scraper alsoincludes a scraping surface spaced a predetermined distance from asurface of the roller along an entire extent of the roller.

Another aspect of the present invention is that the roller is crowned ata center point of the roller. The roller scraper also includes acentrally located ridge associated with the crowned center point of theroller.

Another aspect of the present invention is that the roller scraper alsoincludes a pair of sloping sides extending from the ridge to outer edgesof the roller scraper and following a rollout of the roller to directdebris away from the roller and the conveyor belt.

Another aspect of the present invention is that the conveyor assemblyalso includes a liquid delivery assembly associated with the roller andthe roller scraper. The liquid delivery assembly includes at least onehose, at least one spout, and at least one nozzle associated with eachat least one spout.

Another apparatus in accordance with the principles of the presentinvention may also include a debris skirt. The debris skirt may includeat least one connector disposed along a side of the skirt. The debrisskirt may also include an extension flange disposed along a first end.The debris skirt may also include a mitered section disposed at a secondend and a convex central portion. The skirt is adapted to lift an edgeof a conveyor belt and provide a dynamic seal between the belt and theskirt.

Another aspect of the present invention is that the debris skirt isadapted to be connected to a rub rail at the mitered section. The skirtand rub rail cooperatively lift the edge of the conveyor belt andprovide a dynamic seal between the skirt and rub rail along a length ofthe conveyor belt.

A method in accordance with the principles of the present invention mayalso include a method of preventing debris from traveling over an edgeof a conveyor belt. The method may include lifting the peripheral edgesof the belt and abutting a flange into engagement with a bottom edge ofthe conveyor belt such that the edge of the conveyor belt is lifted intoa concave orientation directing a flow of debris from the flange to aplace away from the belt. Debris is directed toward a center of theconveyor belt and prevented from traveling over the edge of the conveyorbelt. A flange abutment prevents debris from being associated with theunderside surface of the belt.

Another aspect of the present invention may also include connecting arub rail extension to an end of the skirt via a mitered connection andforming a dynamic seal between the connected skirt and rub rail and theconveyor belt along a length of the conveyor belt.

Another method in accordance with the principles of the presentinvention may also include a method of removing debris from a roller.The method may include scraping the surface of a roller such that ascraping surface of a scraper maintains a predetermined spacing from theroller. The method may also include enveloping at least a portion of theroller within the scraper and scraping debris from the roller along andentire length of the roller at plural locations about a circumference ofthe roller.

Another aspect of the present invention may also include directingscraped debris away from a center of the roller and toward ends of theroller and preventing scraped debris from being reattached to theroller.

Another apparatus in accordance with the principles of the presentinvention may also include a roller scraper for scraping a crownedroller. The apparatus may include a centrally located ridge having aridge width and a pair of sides meeting at the ridge and sloping awayfrom the ridge. Each of the sides may be provided with a scrapingsurface for removing debris attached to the roller. Each of the sideshas an end having an end width and a center having a center width. Theend width is greater than the ridge width and the ridge width is greaterthan the center width.

Another aspect of the present invention may also include that the rollerscraper receives a portion of the roller into a portion of the rollerscraper.

Another aspect of the present invention may also include that thecrowned roller has an end diameter at ends of the roller and a crowndiameter at a center point of the roller. The crown diameter is greaterthan the end diameter. The ridge of the roller scraper is associatedwith the center point of the roller and the ends of the sides of thescraper are associated with the ends of the roller.

Another aspect of the present invention may also include scrapingsurfaces following an arcuate curvature corresponding to a path oftraverse across a surface of the roller.

Another aspect of the present invention may also include that the rollerscraper is generally chevron shaped in cross-section.

Another aspect of the present invention may also include that thescraping surfaces selected from smooth edge surfaces and serrated edgessurfaces following a scalloped curvature about each sloping side of thescraper.

The foregoing objects, advantages and distinctions of the invention,among others, are obtained in a presently preferred construction thatprovides a street sweeper having a conveyor belt debris removal system.The conveyor belt debris removal system may be provided with anapparatus configured to form the belt into a particular shape along atleast a portion of the run of the conveyor belt. The conveyor beltdebris removal system may also be provided with a cleaning mechanism forremoving debris from a conveyor belt roller disposed at ends of theconveyor belt apparatus. The foregoing features may be inventions aloneor in combination.

These and various other advantages and features of novelty whichcharacterize the invention are pointed out with particularity in theclaims annexed hereto and forming a part hereof. However, for a betterunderstanding of the invention, its advantages, and the objects obtainedby its use, reference should be made to the drawings which form afurther part hereof, and to accompanying descriptive matter, in whichthere are illustrated and described specific examples of an apparatus inaccordance with the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 illustrates a conveyor assembly with the conveyor belt removedaccording to an embodiment of the present invention;

FIG. 2 illustrates a crowned roller according to an embodiment of thepresent invention;

FIG. 3 illustrates a debris skirt and rub rail according to anembodiment of the present invention;

FIG. 4 illustrates a protective flange extension of the debris skirtaccording to an embodiment of the present invention;

FIG. 5 illustrates the relationship between the debris skirt, roller,and conveyor belt from above according to an embodiment of the presentinvention;

FIG. 6 is an end perspective view of the conveyor assembly illustratingthe relationship between the debris skirts, roller, and conveyor beltaccording to an embodiment of the present invention;

FIGS. 6 a and 6 b are an ends view of the conveyor assembly illustratingthe concave curvature imposed on the conveyor belt by the debris skirtsaccording to an embodiment of the present invention with FIG. 6 bshowing the configuration with a crowned roller;

FIG. 7 illustrates a prior art roller scraper for removing debris from aroller;

FIG. 8 illustrates the roller scraper removing debris from the rollerand enveloping at least a portion of the roller and a liquid dispensingapparatus for cleaning the roller and directing the debris toward theexterior of the conveyor belt according to an embodiment of the presentinvention;

FIG. 9 is a perspective view illustrating the relationship between theroller and the roller scraper according to an embodiment of the presentinvention;

FIG. 10 illustrates the roller scraper according to an embodiment of thepresent invention; and

FIG. 11 is a top perspective view of an alternative scraper.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail herein. It is to be understood,however, that the intention is not limited to the invention shown in theparticular embodiments described. On the contrary, the invention isintended to cover all modifications, equivalents, and alternativesfalling within the scope of the invention as defined by the claimsappended hereto.

DETAILED DESCRIPTION OF THE INVENTION

In the following description of the illustrated embodiments, referenceis made to the accompanying drawings which form a part hereof, and inwhich is shown by way of illustration, various embodiments in which theinvention may be practiced. It is to be understood that otherembodiments may be utilized, and structural and functional changes maybe made without departing from the scope of the present invention.

The present invention provides a street sweeper having a conveyor beltdebris removal system. The debris removal system may be provided with aapparatus configured to form the belt into a particular shape along atleast a portion of the run of the conveyor belt. The debris removalsystem may also be provided with a cleaning mechanism for removingdebris from a conveyor roller disposed at ends of the conveyor assembly.

The present invention discloses street sweepers using a conveyor belt totransport material. The invention may include at least one debris skirtinstalled adjacent the lower roller of the conveyor assembly andadjacent the conveyor belt edges to prevent debris deposited upon theconveyor belt by the main broom from becoming associated with the lowerroller of the conveyor assembly. The debris skirt may be a panel whichprovides a seal between the conveyor belt and the sides of the conveyorassembly. The debris skirt receives a lot of wear by virtue of itsengagement with the conveyor belt while preventing wear on othercomponents of the conveyor assembly.

The conveyor assembly may also be provided with a rub rail disposed on atop face of the conveyor assembly. At least one rub rail may beinstalled where an outer edge of the conveyor belt rides upon theconveyor assembly. The rub rail may also be considered a replaceablewear item along with the debris skirts. The rub rails are adapted toperform at least the following two functions. The rub rails may beadapted to force the conveyor belt to bend into a concave shape whereinthe conveyor belt is forced into a position where the middle portion isdisposed lower than the outer edge portions of the conveyor belt. Inthis manner, the debris may become centralized in the central portion ofthe conveyor belt to prevent the debris from falling over the outeredges of the conveyor belt and damaging other components of the debrisremoval system. The rub rail also provides a dynamic seal between theconveyor belt and the conveyor assembly preventing debris from beingdeposited under the conveyor belt and becoming associated with the lowerroller.

The rub rail and the debris skirt may also be adapted to cooperativelyfunction to prevent debris from falling from the conveyor belt andbecoming associated with the lower roller. The debris skirt may bedisposed in close proximity to the roller at an end of the conveyorassembly to initiate the bending of the conveyor belt by lifting theouter edges of the conveyor. The rub rail may be disposed adjacent tothe distal end of the debris skirt through a mitered connection tocontinue and maintain the concave curvature of the conveyor belt alongthe length of the conveyor assembly. In this fashion, the debris skirtand rub rail lift the conveyor belt's outer edge forcing the belt into aconcave shape and preventing debris from falling over the edge of thebelt.

Unfortunately, debris may still arrive beneath the conveyor belt andcome into contact with the rollers. Some debris may be fine airborneparticles, such as, dust, soot, or road treatment chemicals whichthrough a process similar to condensation may become attached to therollers of the conveyor assembly underneath the conveyor belt.Eventually, a significant number of particles will become attached tothe rollers, causing the belt to slip and/or stretch. Further, theaccumulated debris on the rollers may cause the drive system to workharder requiring more fuel to power the conveyor assembly. The belt mayalso begin to be warped and drift toward the edges of the conveyor sidewalls increasing the wear on both the conveyor belt and the conveyorguide structures.

It is necessary to remove the debris from the rollers before any damageor unnecessary wear can occur. The present invention provides a rollerscraper adapted to remove debris from the rollers. The roller scraper isalso adapted to cause the debris to be directed away from the centerportion of the rollers toward the outer edges of the rollers. Thepresent invention provides a roller scraper adapted to envelop at leasta portion of the roller placing a scraping edge a predetermined distancefrom the roller along the length of the scraper. The scraper roller isadapted to take advantage of gravity in removing and directing thedebris away from the center of the roller by being provided with a highcentral point proximate the center of the roller which slopes downwardlyaway from the center toward both edges of the roller while yetmaintaining the spacing distance between the roller scraper and theroller.

FIG. 1 illustrates a conveyor assembly 100 with the conveyor beltremoved according to an embodiment of the present invention. In FIG. 1,the conveyor assembly 100 is shown having two sidewalls 102 and 104 anda pair of crowned rollers 108 and 110, though only one roller may becrowned. Ordinarily, one roller 108 is a drive roller causing theconveyor belt to rotate and the other roller 110 is a free roller,however, both or either of the rollers 108 and 110 may be driven, ifdesirable. The conveyor assembly 100 is also provided with a debrisskirt 120 and an associated rub rail 130 which are adapted to raise andbend the edge of the conveyor belt causing the belt to take a generallyconcave shape. The conveyor assembly 100 is also provided with a rollerscraper 140 placed in a close and generally enveloping configurationadjacent roller 110 to remove accumulated debris from the roller 110.

FIG. 2 illustrates a perspective view 100 of a crowned roller 210according to an embodiment of the present invention. In FIG. 2, theroller 210 is shown disposed on an axle 215 at respective ends 211 and212 of the roller 210. The axle establishes a longitudinal axis ofrotation for the roller lying in a horizontal plane parallel to theplane of the conveyor belt. The roller is shown crowned at a centerpoint 213 of the roller 210 and have sloped portion 216 and 214 slopingfrom the center point 213 out to the ends 211 and 212. The crowning istypically between 0.15 to 0.75 inches, that is, the central crownedportion of the roller is had an outside diameter between 0.15 to 0.75inches larger than the outside diameter of the roller ends. The roller,for example may be approximately 25 inches in length and have a centralcrowned portion having an outside diameter of 0.375 larger than thediameter of the roller ends. Providing the roller 210 being crowned, asshown in FIG. 2, maintains the conveyor belt located centrally on theroller 210 and prevents the roller from shifting toward either of theends 211, 212 of the roller 210. However, the conveyor belt and roller210 relationship is adversely affected by accumulation of debris on theroller 210 which will change the shape of the roller and cause the beltto slip or shift toward an end of the roller. As debris accumulates onthe roller, the diameter of the roller changes causing the belt tobecome distended and shifting the belt out of the desired orientation.

FIG. 3 is a perspective view 300 illustrating a debris skirt 320 and arub rail 330 connected to an interior sidewall 304 of the conveyorassembly according to an embodiment of the present invention. The debrisskirt 320 is provided with a plurality of brackets 321 and bolts 323 tosecure connect the debris skirt 320 to the sidewall 304. The debrisskirt 320 is provided with an extension flange 366 which at leastpartially covers the junction of the roller axle and bearing (not shownin this figure) where the axle is joined to the sidewall. The extensionflange 366 prevents debris from becoming associated with the axle andbearing interface ensuring that the roller is free to rotate.

The debris skirt 320 is also associated with a rub rail 330 which may beplaced adjacent one another via a mitered joint as shown in FIG. 3. Thedebris skirt 320 and rub rail 330 cause the conveyor belt to be liftedabove the central portion of the conveyor belt directing debris towardthe center of the belt and away from the edge of the belt. In thismanner, the debris is more effectively conveyed to a debris collectionhopper in the street sweeper. The debris is also prevented from fallingover the edge of the conveyor belt preventing the debris fromaccumulating on the opposite surface of the belt or on the rollers whichwould adversely affect the operation of the conveyor assembly.

The debris skirt 320 and rub rail 330 also prevent the conveyor beltfrom shifting from side to side and detrimentally interacting with thesidewalls of the conveyor assembly. The debris skirt 320 and rub rail330 receive the wear instead of the sidewalls and are adapted to beeasily removed and replaced when excessively worn or damaged. The debrisskirt may be sloped downwardly and beneath the edge of the conveyor beltor may be provided with a convex surface to provide a better sealbetween the debris skirt 320 and the conveyor belt. Together the rubrail 330 and the debris skirt form a dynamic seal between the movingconveyor belt and the skirt and rail.

FIG. 4 is a close-up view 400 illustrating the protective extensionflange 466 of the debris skirt 420 according to an embodiment of thepresent invention. In FIG. 4, the extension flange 466 is shownsubstantially covering the interface between the roller 410, the axle415, and the axle bearing 417 to prevent debris from becoming associatedwith moving components of the conveyor assembly.

FIG. 5 is a close-up perspective view 500 illustrating the relationshipbetween the debris skirt 520, roller 510, and conveyor belt 570 fromabove according to an embodiment of the present invention. In FIG. 5,the debris skirt 520 is shown bolted to the sidewall 502 with brackets521 and bolts 523. The debris skirt 520 is shown disposed beneath theedge of the conveyor belt 570 to lift the edge of the belt 570 forcingthe belt into a concave curvature. The debris skirt 520 is shownprovided with an extension flange 566 covering the axle 515 on which theroller 510 rotates. The conveyor belt 570 is shown provided with aflight or cleat 575 across the width thereof. The flight 575 on the belt570 acts to scoop the debris as the conveyor belt rolls and elevates thedebris. The conveyor belt may be fabricated from an ultra-high molecularweight rubber or plastic.

FIG. 6 is an end perspective view 600 of the conveyor assemblyillustrating the relationship between the debris skirts 620, roller 610,and conveyor belt 670 according to an embodiment of the presentinvention. In FIG. 6, debris skirts 620 have been mounted to bothsidewalls 602 and 604 with brackets 621 and bolts. The debris skirts 620are shown disposed beneath the edges of the conveyor belt 670 such thatthe center of the belt is disposed lower than the edges of the beltforcing the conveyor belt to be generally concave shaped across thewidth of the belt with a crowned center adjacent the crowned roller 610.The flights 675 also take on the concave shape of the belt 670. Thedebris skirts 620 are again shown provided with extension flanges 666 tocover and protect the axle 615, roller 610, and bearing interfaces.

FIG. 6 a is an end view 600 a of the conveyor assembly illustrating theconcave curvature imposed on the conveyor belt 670 a by the debrisskirts 620 a and illustrating the relationship between the debris skirts620 a, roller 610 a, and conveyor belt 670 a according to an embodimentof the present invention. In FIG. 6 a, debris skirts 620 a have beenmounted to both sidewalls 602 a and 604 a with brackets 621 a and bolts623 a. The debris skirts 620 a are shown disposed beneath the edges ofthe conveyor belt 670 a such that the center 669 a of the belt isdisposed lower than the edges of the belt 670 a forcing the conveyorbelt 670 a to be generally concave shaped across the width of the belt670 a. The flights 675 a also take on the concave shape of the belt 670a in the region where the belt is formed into the concave shape. Thedebris skirts 620 a are again shown provided with extension flanges 666a to cover and protect the axle 615 a, roller 610 a, and bearinginterfaces.

FIG. 7 is a side view 700 illustrating a prior art roller scraper 781removing debris particles 799 from the roller 712 mounted on axle 715.The prior art scraper 781 is a flat blade with a scraping surface 797placed in close proximity to the roller 712 at a location between theconveyor belt 770 upper and lower segments, i.e., between the sides ofthe belt 770 opposite the flights 775. Debris accumulated on the roller712 is scraped from the roller and falls onto the interior portion ofthe conveyor belt 770, and immediately is re-associated with the roller712 in a continuous cycle as the belt 770 moves along the prescribeddirection of travel 791. The debris particles 799 are not effectivelyremoved from the conveyor assembly but rather are recycled within theassembly.

FIG. 8 is a side view 800 illustrating the roller scraper 880 removingdebris particles 899 from the roller 812 mounted on axle 815 andenveloping at least a portion of the roller 812 and a liquid dispensingapparatus 871, 872, and 873 for cleaning the roller 812 and directingthe debris particles 899 toward the exterior of the conveyor belt 870according to an embodiment of the present invention. The roller scraper880 is provided with a scraping surface 897. The scraping surface may beflat or serrated as desired. The scraping surface is arcuately shaped toconform with the shape of the roller when placed in proximity thereto.

The debris particles 899 are directed away from the center of theinterior space between the upper and lower belt segments by a slopingsurface 882. The scraper 880 is higher at the portion where the scraperlies adjacent to the center of the roller 812 and slopes gently downtoward the outer ends of the roller 812. Thus, the debris particles 899are directed out of the interior of the conveyor assembly by gravitydown the sloping sides of the scraper 880 and by the curved arcuateshape of the scraping surface 897.

The scraper 880 may be optimized by adjusting the spacing between thescraping surface 897 of the scraper 880 and the outer surface of theroller 812 and the slope of sloping sides of the scraper 880. Thescraper's 880 overall shape is preferably a sloped chevron shaped butmay also be other shapes as desired. The scraper 880 may also beoptimized by maximizing the roller runout, i.e., the amount of theroller that is enveloped by the scraper.

The roller runout is based on the limitations of the size of theinterior space between the upper and lower segments of the conveyorbelt. The interior space is based upon the diameter of the roller. Byproviding the scraper surface being arcuate and curved to maintain apredetermined spacing between the roller surface and the scrapingsurface and the entire length of the scraping surface, debris is removedfrom the interior portion of the conveyor assembly. The scraper may befabricated from a hardened steel such as Domex™ steel or other wearhardened metals.

The conveyor assembly may also be provided with a liquid or solventdispensing apparatus. A hose 871 may be disposed in close proximity tothe interface between the scraper 880 and roller 812 to deliver water,detergent, or some other solvent to the roller. The solvent may beadapted to remove difficult gummy substances which would merely besmeared over the roller and not removed therefrom. The hose 871 may bejoined by at least one spout 872. The spout may ideally be provided witha nozzle to disperse the solvent evenly across the roller and providethe solvent with a pressurized delivery. Preferably, the liquid deliveryapparatus would be provided with a sufficient number of spouts andnozzles to completely and evenly cover the entire width of the rollerwith solvent nearly simultaneously.

FIG. 9 is a perspective view 900 illustrating the relationship betweenthe roller 910 and the roller scraper 980 according to an embodiment ofthe present invention. In FIG. 9, the roller 910 is mounted on axle 915at ends 911 and 912. The axle establishes a central axis of rotation forthe roller and lies in a horizontal plane generally parallel to theplane of the conveyor belt. The ridge 988 of the scraper 980 ispreferably a chevron shape and is configured to approach the crown 913of the crowned portion of the roller and lie adjacent the crown 913preferably without touching. The scraping surfaces 997 on each side 984,986 of the scraper 980 are configured arcuately curved in order tomaintain spacing between the scraping surface 997 and the roller 910from the crown 913 of the roller 910 out to the apex or edge where theroller surface meets the roller ends 911, 912 and envelop the roller 910adjacent to the sloping sides 914 of the roller 910. Debris scraped fromthe roller 910 by the scraper 980 is directed away from the center ofthe roller to the exterior ends of the roller by both the accelerationof gravity by the curved sloping shape of the roller scraper 980.

FIG. 10 is a perspective view 1000 illustrating the roller scraper 1080according to an embodiment of the present invention. In FIG. 10, theroller scraper 1080 is shown having a ridge portion 1088, a pair ofscraping surfaces 1081 extending along sloping sides 1084 and 1086 ofthe roller scraper. The ridge portion may be configured to be furtherupstream of the scraper portions 1081. That is, the ridge may extendcircumferentially around the roller generally along the crown point 913(FIG. 9) and the leading edge of the scraper 1081 will preferably followa slightly arcuate path from the ridge to the sides 1084. In effect, thescraper will preferably follow an arc which wraps around the roller(envelopes) as it tails out toward the ends 1084. This provides a smoothpath for debris to be removed. In the alternative, the path may bestraight. In the preferred case, the width of the scraper is greater atthe ends 1084 than at the ridge. The scraper roller 1080 may beconfigured to extend across the entire width of a roller or may be usedin a plural scraper configuration on a long roller having a plurality ofconveyor belts disposed thereon.

FIG. 11 illustrates an alternative embodiment designed to permit easyreplacement of the scraper blades. Removably affixed atop the bladesupport surface 1186, is an adjustable and replaceable blade portion1110 (shown only on one side but in the preferred configuration, itwould appear on both sides of the scraper assembly. Blade 1110 isaffixed to the base 1186 via longitudinal slot which are generallyperpendicular to the roller 910 but provide sufficient width to permitthe blade to be skewed as desired relative to the roller. The blade isthe bolted to the base 1186 with the threaded holes 1114. The preferredmaterial for the removable blades is AR400 and the preferred spacingfrom the roller is 0.125 inches/3 mm. The advantage of this constructionis that the base 1186 can be made of a variety of materials while theblade can me made of special hardened materials and replaced as needed.It is also possible to shape the leading edge 1181 of the blade toconform to any special curvature or crowing of the roller as needed forthe circumstance.

The roller scraper may also have a crown diameter which is greater thanthe end diameter, and the ridge of the roller scraper which isassociated with the center point of the roller and the ends of the sidesof the scraper are associated with the ends of the roller.Further, it is understood that the roller scraper and the debris skirtstructures may be combined or used separated as needed for theparticular configuration. Therefore, if the two features are combined,the shape of the conveyor belt 675 a in FIG. 6 b will be altered to risetoward the center (apex 699 b) where the roller's crown is located andat the end(s) 699 c thereby creating two slight troughs 699 d.

It is understood that alternate structures for the a street sweeperhaving a conveyor belt debris removal system may be provided withoutdeparting from the scope of the invention.

The foregoing objects, advantages and distinctions of the invention,among others, are obtained in a presently preferred construction thatprovides a conveyor belt debris removal system provided with anapparatus configured to form the belt into a particular shape along atleast a portion of the run of the conveyor belt and a conveyor beltdebris removal system provided with a cleaning mechanism for removingdebris from a conveyor belt roller disposed at ends of the conveyor beltapparatus.

The foregoing description of an exemplary embodiment of the inventionhas been presented for the purpose of illustration and description. Itis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the above teaching. It is intended that the scope of theinvention be limited not with this detained description, but rather bythe claims appended hereto.

1. A conveyor assembly having peripheral sidewalls, the assemblycomprising: a first driving roller; a second roller mounted on an axlehaving an associated bearing assembly at each end of the axle; aconveyor belt having opposing edges and top and underside surfaces,said, the belt being operatively connected to the driving roller and thesecond roller and defining a gap between one of the sidewalls and belt;and at least one non-moving debris skirt associated with an edge of theconveyor belt, wherein the debris skirt extending from one of saidsidewall and being positioned to lift the edge of the conveyor belt,thereby causing the conveyor belt to follow a concave orientation, and;wherein a portion of said non-moving skirt overlies a portion of one ofsaid rollers and its axles, thereby preventing debris from accumulatingon the underside of the belt via the gap adjacent one of the rollers andits axles and wherein the at least one debris skirt further comprises apair of debris skirts extending from said sidewalls, each debris skirtassociated with opposing edges of the conveyor belt adjacent to thesecond roller and; wherein each debris skirt further comprises anextension flange substantially covering at least part of the ends of theaxle and the associated bearing assemblies, and; further comprising aplurality of spaced apart rub rails associated with each debris skirt,wherein the debris skirt and associated rub rail cooperatively provide alow friction gliding surface and form a dynamic seal with the conveyorbelt along the edges of the conveyor belt and cooperatively lift theconveyor belt edges along a length of the conveyor belt to deflect theedges of the belt to form a concave shape; and wherein the rub rail andthe debris skirt are associated via a mitered joint.
 2. The conveyor ofclaim 1, further comprising a roller scraper associated with a roller,wherein the roller scraper envelops at least a portion of the rollerand; wherein the roller scraper further comprises a pair of slopingsides extending from the ridge to outer edges of the roller scraper andfollowing a rollout of the second roller to direct debris away from thesecond roller and the conveyor belt.
 3. The conveyor of claim 2 whereinsaid scraper includes an adjustable blade portion.
 4. A conveyorassembly having peripheral sidewalls, the assembly comprising: a firstdriving roller; a second roller mounted on an axle having an associatedbearing assembly at each end of the axle; a conveyor belt havingopposing edges and top and underside surfaces, said, the belt beingoperatively connected to the driving roller and the second roller anddefining a gap between one of the sidewalls and belt; and at least onenon-moving debris skirt associated with an edge of the conveyor belt,wherein the debris skirt extending from one of said sidewall; and beingpositioned to lift the edge of the conveyor belt, thereby causing theconveyor belt to follow a concave orientation, and; wherein a portion ofsaid non-moving skirt overlies a portion of one of said rollers and itsaxles, thereby preventing debris from accumulating on the underside ofthe belt via the gap adjacent one of the rollers and its axles; andfurther comprising a roller scraper associated with a roller, whereinthe roller scraper envelops; and wherein the roller scraper furthercomprises a scraping surface spaced a predetermined distance from asurface of the roller along the roller; and wherein second roller iscrowned at a center point of the roller and the roller scraper furthercomprises a centrally located ridge associated with the crowned centerpoint of the second roller.
 5. A conveyor assembly comprising: a rollermounted on an axle having an associated bearing assembly at each end ofthe axle; a conveyor belt operatively connected to the roller; and apair of opposing debris skirts associated with each edge of the conveyorbelt, and a plurality of spaced apart rub rails for supporting saidbelt, said rails also being spaced from each other and wherein thedebris skirts lift the edge of the conveyor belt forming the conveyorbelt into a concave orientation and where said belt is suspended betweensaid skirt and said rub rails so that a dynamic seal between said belt,said axles and said skirt prevent debris from getting to the undersideof the belt; and further comprising a roller scraper associated with theroller, wherein the roller scraper envelops at least a portion of theroller; and wherein the roller scraper further comprises a scrapingsurface spaced a predetermined distance from a surface of the rolleralong an entire extent of the roller; and wherein roller is crowned at acenter point of the roller and the roller scraper further comprises acentrally located ridge associated with the crowned center point of theroller.
 6. The conveyor assembly of claim 5, wherein the rub rail andthe debris skirt are associated via a mitered connection.
 7. Theconveyor assembly of claim 5, wherein the roller scraper furthercomprises a pair of sloping sides extending from the ridge to outeredges of the roller scraper and following a rollout of the roller todirect debris away from the roller and the conveyor belt.
 8. Theconveyor assembly of claim 7, further comprising a liquid deliveryassembly associated with the roller and the roller scraper, wherein theliquid delivery assembly comprises a hose, at least one spout, and anozzle associated with each at least one spout.
 9. A debris skirt foruse with a conveyor belt comprising: at least one connector disposedalong a side of the skirt; an extension flange disposed along a firstend; a mitered section disposed at a second end; and a convex centralportion of a conveyor belt, wherein the skirt is adapted to lift an edgeof a conveyor belt and provide a dynamic seal between the belt and theskirt.
 10. The debris skirt of claim 9, wherein the debris skirt isadapted to be connected to a rub rail at the mitered section, whereinthe skirt and rub rail cooperatively lift the edge of the conveyor beltand provide a dynamic seal between the skirt and rub rail along a lengthof the conveyor belt.
 11. A method of preventing debris from travelingover an edge of a conveyor belt, the method comprising: lifting theperipheral edges of the belt with a lifting skirt; and abutting thelifting skirt into engagement with a bottom edge of the conveyor beltsuch that the edge of the conveyor belt is lifted into a concaveorientation directing a flow of debris from the flange to a place awayfrom the belt, wherein debris is directed toward a center of theconveyor belt and prevented from traveling over the edge of the conveyorbelt, and wherein flange abutment prevents debris from being associatedwith the underside surface of the belt; and connecting a rub railextension to an end of the skirt via a mitered connection; and forming adynamic seal between the connected skirt and rub rail and the conveyorbelt along a length of the conveyor belt.